Rotary snap switch



8 195 0 A. l. APPLETON ETAL 2,519,215

ROTARY SNAP SWITCH Filed Aug. 27, 1949 Inventors arthur Lqjpleton norm 0 424) la ton i (While the Patented Aug. 15 1950 UNITED" STATES PATENT if ROTARY SNAEP SWITCH Arthur I. Appleton, Northhrook, and Norton A.

Appleton, Chicago, Ill.,"a.ssignors to Appleton I it Electric Company, Chicago, 111., a corporation of Illinois Application August 27, 1949, ScrialNo. 112,796

wtive action and which will perform reliably over a relatively long life.

Another object is to "provide a rotary snap switch of rugged and simple construction which will lend itself to economicalmanufacture on a mass production basis largely from molded plastie and stamped sheet-metalparts.

Other objects and advantages'will become apparent :as the following detailed description proceeds, taken in connection with the accompanying drawings, wherein: r

Figure l is an elevation of an automobile spotlight handle which has been adapted'to house an illustrative switch embodyingthe present invention. 1

Fig. 2 is an enlarged fragmentary sectional view taken longitudinally through the switch shown in Fig. 1 and in the plane of the line 2-2.

Fig. 3 is an exploded perspective view detailiing various component parts of the switch.

Figs. 4 and 5 are fragmentary transversesectional views of the switchtaken in the plane of the line 4-4 in Fig. 2 and showing the rotary .open circuit conditions the relationship between the rotary contact member and certain parts fixed to the terminal block, such views being taken respectively in'the plane of the line 6--T.6

in Fig. 4' and in the plane of the line 'l--1 Fig. 5.

invention is susceptible of "various modifications and alternative"constructions, a preferred embodiment hasbeen shown in the drawings and will be described below in considerable detail. It should be:unders tood,;however,

that there is no intention to limit the invention to the specific form disclosed, :but on the conplary rotary snap switch embodying the inven Claims. (Cl. 200-63) within the handle ll of an automobile spotlight. The switch It) comprises a terminal block I201 molded phenolic plastic or the like,together with r a rotary contact disc 14 and an actuating cap 15. :These members are secured together by means et an assembly screw l6 with-an approximate compression spring I8 interposed between thecap 15 and the rotary contact disc I4.

In the present instance, the terminal block I is substantially cylindrical in shape, being of peripheral lugs 21 (Fig. 3). The outer face'of the block 12 has an annular recess defining there- I in a skirt 22 and a central bearing boss 24. The :-latter has a centrally located, tapped hole-26 for receiving the threaded end of the assemblyscrew :16. Mounted in diametrically opposed relation 'on the floor of the recess are stationary contacts 28 which, in the present instance, consti tute rounded heads of a pair of rivets 29; These serve as conductors and also as mechanical fasteners for terminal lugs 39 on the underside of theblocklz. Provision is made in the'switch It! for'closing Tand opening the circuit" between the stationam contacts .28 as an incident torotation of the contact disc 14 through a'relatively small angle in 1 either direction. Accordingly, the disc i4 is-J'our- 'naled on bearing boss 24; beingformed with a central aperture surrounded by a bearing'flange "3|. In order to define a plurality of closed circuit circumferentially spaced holes 32,- all of which are located at the same radial distance from the :center. As indicated in the drawing, the holes '32 are arranged in diametrically opposed. pairs 40' T contacts 28.

positions. the face of the'disc It has a set of which are adapted to register with the stationary To insure good electrical contact betweenthe disc M and-the contacts 28 when the holes 32 are in registration with the latter, the

holes 32 are made of somewhat smaller diameter .might be found desirable totaper'the holes 32 slightly on the underside of the disc so as to create a, clrcu'lar'band of contacting area between'the peripheral'portions of the holes 32 and the contacts 28 with Which'they are associated. I

than the contacts 28. In certain instances it For the purpose of defining a plurality of open circuit positions in the switch Ill, the rotary contact disc 14 is formed with a second set of circum- "ferentially spaced holes 34, the latter beingdistion and housed; .forpurposes of illustration, 5 posed in alternate series relation'wit'h the holes vtion between the holes 32, 34.

'Moreover, when the switch is shifted from the 32. The holes 34 are somewhat larger in diameter than the holes 32 so as to permit registration in diametrically opposed pairs with the con tacts 28 but without having their peripheral portions touch the contacts 28.

In order to insure maintenance of the open circuit condition during registration of the holes 34 and the contacts 28, the floor 25 of the'terminal block recess has a plurality of nonconductive buttons 35 integral therewith. The buttons 35 are spaced so as to register with the smaller holes 32 when the holes 34 are in registration with the contacts 28. Moreover, the buttons 35 are of comparable size to the stationary contacts 28 and when they engage the smaller holes 32, they tend to maintain the disc I4 in such a position that there will be adequate space between the peripheral edges of the openings 34 and the stationary contacts 28. Thus it will be appreciated that the buttons 35 serve to maintain the disc I4 in proper axial as well as circumferential relation with the stationary contacts 28.

For the purpose of minimizing wear upon the contacting members during interruption of the circuit and also to giv the switch It a positive snap action which would enable a driver to operate it readily by sense of touch, the rotary contact member has a set or radial cam embossments interposed in alternate series rela- With this construction, it will be perceived that when the switch is moved from one position to another,

;the embossments 36 will cam over the stationary contacts 28 and the nonconductive buttons 35.

closed circuit to the open circuit position, the electrical break occurs between the embossments 3'6 and thecontacts 28 rather than between the edges of the openings 32 and the contacts 28. This minimizes wear and tear on the current 44 conducting areas and assures longevity of the switch.

Actuation of the switch I0 is effected by rotation of the cap I5 which may be made of plastic or-some other appropriate nonconductiv mate-' 4 rial. Exteriorly, the cap I 5 may be provided with a plurality of peripheral teeth 38 of. appropriate size and shape to enable the cap to be turned merely by thumb pressure. The interior of the cap is hollow and accommodates the assembly screw I6 together with the compression spring I8, the latter being suitably centered in a counterbore 39 concentric with screw opening '48. To connect the cap I5 with the disc I4 positively, the former is fashioned in the present instance with a pair of diametrically opposed driving lugs 4I having segmental recesses 42 which drivingly receive axial ears 44 projecting outwardly from the plane of the rotary contact disc-I4. The cap also has a skirted portion 45 underlying the teeth 38 and extending axially over the end of the handle II to complete the protective housing of the switch.

In operation, the open circuit condition of the switch exists when th larger holes 34 register 165 with the stationary contacts 28 (Figs. 5 and 7) At the same time, the smaller holes 32 register with the nonconductive buttons 35 which maintain the disc I4 in spaced relation from the contacts 28. If the cap I5 is subsequently turnedg' o in either direction, th radial embossments 36 will cam over the stationary contacts 28 and the member I4 to snap into its new. position as thee- 4 spring expands (Figs. 4 and 6). When this occurs, a pair of the smaller holes 32 will be brought into registration with the stationary contacts 28 and the larger holes 34 will then register with the nonconductive buttons 35. At this point, th peripheral edges of the holes 32 will make electrical contact with the buttons .28 .and define the closed circuit position of the switch. B the use of several sets of openings arranged in alternate series relation, it will be noted that the switch may be actuated by rotation of the cap l5 through only a relatively slight angle.

In view of the foregoing, it will b apreciated at this point that the switch I 0 possesses a number of important commercial advantages. First of all, the ruggedness and simplicity of the construction used, and in particular the combination of the low inertia rotary contact member I4 with the heavy loading spring I8, are adequate to insure that the switch will be free from the adverse effects of shock and vibration. In addition to the ruggedness of the parts themselves, the switch structure lends itself readily to adequate protective housing which also contributes to its'reliability and performance. The construction utilized also lends itself readily to manufacture of the switch in a wide range of sizes.

Weclaim as our invention:

1. A rotary snap switch comprising the combination of a terminal block having a plurality of stationary contacts and a plurality of nonconductive projections, said contacts and said projections being arranged in circumferentially spaced relation on one face of said terminal block, a nonconductive bearing boss projecting outwardly from said one face of said terminal block, a rotary contact member journaledon said boss and having circumferentially spaced sets of openings therein, one set of openings being substan tially smaller than said other set, said rotary contact member also having a set of embossments projecting toward said one face of said terminal block and spaced alternately with said openings of said contact member, means for actuating said rotary contact member manually, and a resilient member interposed between said means and said rotary contact member for urging the latter toward said one face of said terminal block.

2. A rotary snap switch comprising, in combination, a terminal block having an annular recess in one face thereof, a plurality of stationary contacts and a plurality of nonconductive buttons arranged in circumferentially spaced relation'on the floor of said terminal block recess, an integral bearing boss projecting outwardly from the floor of said terminal block recess, a rotary contact disc journaled on said boss and having alternate sets of holes spaced circumferentially therein, the holes of one of said sets being substantially smaller than those of said other set, said rotary contact disc also having a set of cam embossments projecting toward the floor of said terminal block recess, said cam embossments alternating with said holes of said rotary contact disc, an actuating cap, means defining a positive driving connectionbetween said cap and said rotary contact disc, and a compression loading spring interposed between said cap and said rotary contact disc for maintaining the latter securely against said stationary contacts and said nonconductive buttons. y

:13. A' rotary snap switch comprising, in combination, a, terminal block having an annular recess in one face thereof defining an annular skirt and a central bearing boss, a pair of stationary contacts and a plurality of nonconductive buttons arranged in circumferentially spaced relation on the floor of said terminal block recess,

a a rotary contact disc of stamped sheet metal journaled on said boss and having alternate sets of circular holes spaced circumferentially therein,

the holes of one of said sets being substantially smaller in diameter than those of said other set and said stationary contacts, a pair of ears extending axially from said rotary contact disc, a hollow actuating cap having means adapted to engage said ears to define a positive driving connection between said cap and said rotary contact disc, and a compression spring interposed between said cap and said rotary contact disc for maintaining the latter securely against said stationary contacts and said nonconductive buttons.

4. In a rotary snap switch, an integral rotary contact member of stamped sheet metal and comprising, in combination, a disc having a central bearing aperture, said disc also having first and second sets of openings therein, the openings of said first set being disposed in alternate and circumferentially spaced relation with those of said second set and also being of substantially larger size, a plurality of cam embossments in said disc, said embossments being interposed between adjacent openings of each of said sets, and means for coupling said disc to a manual actuating member.

5. In a rotary snap switch, an integral rotary contact member comprising the combination of a disc having a central aperture surrounded by a bearing flange, said disc also having therein a first and a second set of holes disposed in alternate and circumferentially spaced relation, the holes of one of said sets being of substantially larger size than the holes of said other set, a plurality of radial cam embossments interposed in alternate series relation with the holes of each of said sets, and a pair of axially extending ears for transmitting an actuating torque to said disc.

ARTHUR I. APPLETQN. NORTON A. .APPLETON.

No references cited. 

